A charging roller, attached to electrophotographic image forming apparatuses so as to charge photoreceptor drums, has been conventionally known. The charging roller has a shaft and a charge emission member (roller main body) attached to the shaft, and charge a photoreceptor drum by means of an electric charge emitted from the charge emission member.
A charging roller, as disclosed in Patent Literature 1, has been conventionally known in which a gap retaining member, attached to a part of a charge emission member, is caused to be in contact with a photoreceptor drum. This allows the photoreceptor drum and the charge emission member to be out-of-contact with each other.
However, such a charging roller has caused a problem that a partial deterioration occurs at a boundary, in the charge emission member, between an area where the gap retaining member is attached and an area where no retaining member is attached. In order to address such a problem, Patent Literature 1 discloses as follows. That is, in a case where an old gap retaining member is released to be replaced by a new one, the new gap retaining member which has an area, to be attached to the charge emission member, larger than the old gap retaining member.